1998–99 Primeira Divisão
The 1998–99 Primeira Divisão was the 65th edition of top flight of Portuguese football. It started on 23 August 1998 with a match between Chaves and Académica Coimbra, and ended on 30 May 1999. The league was contested by 18 clubs with Porto as the defending champions.
Porto won the league and qualified for the 1999–2000 UEFA Champions League group stage, along with Boavista, who qualified for the third round. With the extinction of the UEFA Cup Winners' Cup, the Taça de Portugal winner qualified for the UEFA Cup, so Beira-Mar joined Benfica, Sporting CP and Vitória de Setúbal in the 1999-2000 UEFA Cup; in opposite, Beira-Mar, Chaves and Académica Coimbra were relegated to the Liga de Honra. Mário Jardel was the top scorer with 36 goals.
Promotion and relegation
Teams relegated to [Liga de Honra]
- Leça
- Varzim
- Belenenses
Teams promoted from Liga de Honra
- União de Leiria
- Beira-Mar
- Alverca
Teams
Stadia and locations
| Team | Head Coach | City | Stadium | 1997–98 finish |
| Académica Coimbra |  Raul Águas | Coimbra | Estádio Cidade de Coimbra | 15th |
| Alverca |  Mário Wilson | Alverca | Complexo do Alverca | 3rd in Divisão de Honra |
| Beira-Mar | António Sousa | Aveiro | Estádio Mário Duarte | 2nd in Divisão de Honra |
| Benfica |  Graeme Souness | Lisbon | Estádio da Luz | 2nd |
| Boavista | Jaime Pacheco | Porto | Estádio do Bessa | 6th |
| Braga | Vítor Oliveira | Braga | Estádio Primeiro de Maio | 10th |
| Campomaiorense | João Alves | Campo Maior | Estádio Capitão Cesar Correia | 11th |
| Chaves | Horácio Gonçalves | Chaves | Estádio Municipal de Chaves | 16th |
| Estrela da Amadora | Jorge Jesus | Amadora | Estádio José Gomes | 7th |
| Farense |  Paco Fortes | Faro | Estádio de São Luís | 14th |
| Marítimo | Augusto Inácio | Funchal | Estádio dos Barreiros | 5th |
| Porto | Fernando Santos | Porto | Estádio das Antas | 1st |
| Rio Ave | Carlos Brito | Vila do Conde | Estádio dos Arcos | 9th |
| Salgueiros | Dito | Porto | Estádio Engenheiro Vidal Pinheiro | 8th |
| Sporting CP |  Mirko Jozic | Lisbon | Estádio José Alvalade | 4th |
| União de Leiria | Mário Reis | Leiria | Estádio Dr. Magalhães Pessoa | 1st in Divisão de Honra |
| Vitória de Guimarães |  Zoran Filipovic | Guimarães | Estádio D. Afonso Henriques | 3rd |
| Vitória de Setúbal | Carlos Cardoso | Setúbal | Estádio do Bonfim | 13th |